Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=false), and the description adds real, non-redundant behavior: the checklist array replaces the entire existing list, done=true moves the card into a 'Erledigt' list that is created if missing, and items must be shaped as {text, done}. It leaves two behavioral gaps: whether this is a partial update (only provided fields overwritten) and that 'attachments' likewise replaces the whole list — the latter is only in the schema. The replacement semantics are arguably at odds with destructiveHint=false but the card itself is not destroyed, so this is disclosed tension rather than a contradiction.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

One dense sentence, front-loaded with the verb and resource, then colon-introduced field list — no filler. It is a long run-on with semicolons that packs several distinct behaviors together, which costs a little readability but nothing is wasted.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 12-parameter mutation tool with no output schema and 42% schema coverage, the description covers the most consequential behaviors (array replacement, auto-created Done list, move semantics) but omits the single most important update semantic — that only provided fields are modified — plus five parameters and any hint about the response. Adequate, not complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is only 42% across 12 parameters, so the description has to compensate and it does for about seven of them: title, description, due_date, labels, checklist (with item shape {text, done}), list (name or ID) and done (target list semantics). It says nothing about mine, event_id, position, attachments or task_id, leaving roughly half the parameters documented only by the sparse schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Ändert eine Karte') and enumerates exactly which fields can change (Titel, Beschreibung, Fälligkeit, Labels, Checkliste, list, done). An agent knows immediately this is a partial field-level update of one task. It does not, however, distinguish itself from siblings like update_board, update_calendar_event or delete_task, so it stops short of a 5.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied by 'Ändert eine Karte' but there is no explicit when-to-use / when-not-to-use, no statement that only supplied fields change and omitted ones are left untouched, and no routing to alternatives such as delete_task or add_tasks. The closest thing to guidance is the done/list move semantics, which is behavioral rather than selection guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.